The primary objective of this double-blind, randomized study is to investigate the dose response of postoperative analgesia with intrathecally administered sameridine. The primary measures of efficacy are postoperative pain and consumption of supplmentary analgesics. Sameridine will also be compared to a standard dose of intrathecal lidocaine and the dose relationship to duration of sensory and motor block will be studied. The study was extended in order to accrue additional subjects.